Handle for container, handle-equipped container, and method for manufacturing handle and container

ABSTRACT

The present invention provides a handle for a container, a handle-equipped container, and a method for manufacturing same. It is accordingly possible to provide a container that has a cross-sectional shape that is substantially quadrangular and allows for exceptional storability, has favorable blow-molding properties, presents none of a variety of anomalies in the container and the handle, and has adequate strength to withstand drop impact. 
     The present invention is characterized in comprising a polyester container, which has a finish part, a shoulder part, a body part, and a base part in the stated order from a top part; which has a concavity provided to a portion of the body part; and which has a handle-attaching convexity provided to the concavity; and a polyester handle attached to the handle-attaching convexity of the container. A space is provided between the handle and a wall surface that surrounds the handle-attaching convexity in the concavity. A transverse cross-sectional shape of the body part has a substantially quadrangular shape. The concavity is in a corner part of an upper half part of the body part, and the handle-attaching convexity is positioned in a concavity along a diagonal line L of the upper half part.

TECHNICAL FIELD

The present invention relates to a handle-equipped container that can befilled with tea or other liquids, and in particular to a heat-resistanthandle-equipped container that can be filled with a high-temperatureliquid without deforming the container, and a method for manufacturingthe container. The invention more particularly relates to ahandle-equipped container and method for manufacturing same, wherein atransverse cross-sectional shape of a body part is made substantiallyquadrangular, and a space is provided between a handle and a wallsurface that surrounds a convexity for attaching the handle in aconcavity, whereby the blow-molding properties are improved, whichcreates no incidence of separation between the container and the handle,wrinkling, cracking, irregular thickness caused by deformation orinappropriate stretching, or other anomalies.

The present invention further relates to a handle for a container thatcan be ideally used on the above mentioned container.

BACKGROUND ART

Large-size plastic containers that have a capacity of 1.5 L, 2.0 L, ormore, and are used to store tea, alcoholic drinks, and other beverages;condiments; or the like are often fitted with a handle to improve easeof use. For reasons related to performance and cost, suchhandle-equipped containers are often made from polyethyleneterephthalate or another polyester, and the handle material is oftenmade from polypropylene.

The following are examples of handle-equipped plastic containers thatare known in the art.

Prior Art Document 1: Japanese Laid-open Patent Application No.2000-255580

Prior Art Document 2: Japanese Laid-open Patent Application No.2000-43877

In Prior Art Document 1, the handle is made from the same polyester asthe container to aid recyclability. As shown in FIGS. 9 and 10, thecontainer of Prior Art Document 1 comprises a polyester container g,which has a finish part a, a shoulder part b, a body part c, and a basepart d in the stated order from the top part; which has a concavity eprovided to a portion of the body part c; and which has ahandle-attaching convexity f provided to the concavity e; and apolyester handle h, which is attached to the handle-attaching convexityf of the container g. A space j is provided between the handle h and awall surface i that surrounds the convexity f on the concavity e. As aresult, less frictional resistance occurs in the portion provided withthe space j between the wall surface i that surrounds the convexity fand the handle h; blow-molding ability improves; no incidence ispresented in regard to scratches, melting, or whitening of the concavitye, nor of thickness defects in the concavity e or the base part d; and asatisfactory handle-equipped container can be obtained.

The heat-resistant handle-equipped container according to Prior ArtDocument 2 is obtained as described below. As shown in FIG. 11, theseparate handle h is insert-molded on the body part c of the top part ofthe container g, and the transverse cross section of the body part c ofthe top part to which the handle h is attached is molded into a roundshape. The transverse cross section of the body part c of the base part,to which a reduced-pressure absorption panel k is attached, is moldedinto a quadrangular shape, a side wall of the body part c that enfoldsan undercut part of the handle h is heat set, and the ratio between thearea of the reduced-pressure absorption panel k and the area of thesurface below the neck ring of the finish part a is 0.22 or greater. Asatisfactory handle-equipped heat-resistant container is therebyobtained.

A large demand has arisen over the past several years for plasticcontainers having a quadrangularly shaped transverse cross section inorder to increase the volumetric efficiency during storage andtransport.

The handle-equipped container of Prior Art Document 1 is described ashaving an effect whereby blow-molding properties are improved, andanomalies arising in the concavity e and base part d are eliminated.However, in the examples, mention is only made of the body part having around cross-sectional shape, and no mention is made in regard to anobject of obtaining an angular handle-equipped container, nor toresolving means. Moreover, no mention is made in regard to the impartingof a heat-resisting property that enables high-temperature filling to beperformed.

The body part of the heat-resistant handle-equipped container of PriorArt Document 2 has a quadrangular cross section below the position wherethe handle is attached; however, the upper part where the handle isattached has a round cross-section, which is inadequate for improvingvolumetric efficiency. Favorable heat resistance can be obtained byheat-setting the body part that enfolds an undercut part of the handle.However, the heat-setting is performed on the container wall, whichcontacts the molding mold, and the portion that enfolds the handleundercut part is positioned within the container. Therefore, heatsetting cannot be directly performed, and a concern arises in that thestrength with which the handle is attached will decline as a result ofcontraction and deformation during high temperature filling.

DISCLOSURE OF THE INVENTION

It is therefore an object of present invention to provide aheat-resistant handle-equipped container (and a method for manufacturingsame) that has exceptional storability enabled by having across-sectionally quadrangular shape; favorable blow-molding properties;and minimal incidence of separation between the container and thehandle, wrinkling, cracking, deformation, thickness irregularitiescaused by unsuitable stretching, or other anomalies. The container alsohas sufficient strength against drop impact.

The present invention has been proposed in order to achieve theaforesaid object, and is characterized in comprising the followingstructure.

Specifically, according to [a first aspect of] (*1) the presentinvention there is provided a handle-equipped container, which comprisesa polyester container that has a finish part, a shoulder part, a bodypart, and a base part in the stated order from a top part; and that hasa concavity provided to a portion of the body part; and a separatehandle attached to the concavity. The handle-equipped container ischaracterized in that a transverse cross-sectional shape of the bodypart is substantially quadrangular; the concavity is in a corner part ofan upper half part of the body part; and the handle is attached to theconcavity along a diagonal line of the body part.

According to [a second aspect of] the present invention there isprovided the handle-equipped container [of the first aspect], wherein ahandle-attaching convexity is provided to the concavity; and a space isprovided between the handle and a wall surface that surrounds thehandle-attaching convexity.

According to [a third aspect of] the present invention there is providedthe handle-equipped container [of the second aspect], wherein thehandle-equipped container is a heat-resistant handle-equipped container;and the wall surface that surrounds the convexity for attaching thehandle is heat-set.

According to [a fourth aspect of] the present invention there isprovided the handle-equipped container [of the first through thirdaspects], wherein an end surface of the handle-attaching convexity isformed in the shape of a panel.

According to [a fifth aspect of] the present invention there is providedthe handle-equipped container [of the first through fourth aspects],wherein a longitudinal rib is formed on a corner part of body partconnected to a bottom part of the handle attached to the container.

According to [a sixth aspect of] the present invention there is providedthe handle-equipped container [of the first through fifth aspects],which is formed so that a distance between opposing corner parts on thebottom half of the body part below the handle attachment positiongradually decreases towards the base part.

According to [a seventh aspect of] the present invention there isprovided a handle for a container, characterized in comprising a holdingpart and an attachment part that is attached to a handle-attachingconvexity. The holding part has a transverse cross section in the shapeof an “H,” and an interior plate of the holding part is narrower than anexterior plate.

According to [an eighth aspect of] the present invention there isprovided the handle for a container [of the seventh aspect], wherein thematerial of the handle is a material recycled from articles molded frompolyethylene terephthalate.

According to [a ninth aspect of] the present invention there is provideda method for manufacturing a heat-resistant handle-equipped container,comprising insert-molding a separate polyester handle onto a top part ofa body part of a hollow container when the container is formed byblow-molding a polyester preform. The method for manufacturing aheat-resistant handle-equipped container is characterized in comprisingthe steps of blow-molding with a blow-molding mold positioned so that acentral axis of the body part below a handle-attaching convexityprovided to a concavity on a top half of the body part is inclined1°±0.5° toward the handle-attaching convexity; and heat-setting a wallsurface that surrounds the handle-attaching convexity in the concavity.

According to [a tenth aspect of] the present invention there is providedthe method for manufacturing a heat-resistant handle-equipped container[of the ninth aspect], wherein a surface treatment is performed on atleast some of the blow-molding mold in a region for molding theconcavity of the container and the handle-attaching convexity.

According to [an eleventh aspect of] the present invention there isprovided the method for manufacturing a heat-resistant handle-equippedcontainer [of the ninth and tenth aspects], wherein an insulationtreatment is performed on a region of the blow-molding mold that cancontact the handle during the insert-molding.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a handle-equipped container (heat-resistanthandle-equipped container) that shows a preferred embodiment of thepresent invention;

FIG. 2 is a cross-sectional view across line A-A in FIG. 1;

FIG. 3 is a front view of the handle-equipped container (heat-resistanthandle-equipped container) of the present invention;

FIG. 4 is a cross-sectional view across line B-B in FIG. 3;

FIG. 5 is an enlarged view showing an end view of a panel-shaped endsurface of the present invention, wherein a portion of the handle hasbeen omitted;

FIG. 6 is a rear view of the handle of the present invention;

FIG. 7 is a side view of the handle of the present invention;

FIG. 8 is a cross-sectional view across line X-X line in FIG. 7;

FIG. 9 is a side view that shows an example of a conventionalhandle-equipped container;

FIG. 10 is a side view of a conventional handle-equipped container,wherein an element of the handle has been enlarged; and

FIG. 11 is a side view that shows an example of a conventionalheat-resistant handle-equipped container.

DESCRIPTION OF THE REFERENCE LETTERS AND NUMBERS

The reference letters in the drawings are as follows.

-   1: Handle-equipped container (heat resistant handle-equipped    container)-   2, a: Finish part-   3, b: Shoulder part-   4, c: Body part-   5, d: Base part-   6, e: Concavity-   7, f: Handle-attaching convexity-   8, g: Container-   9, h: Handle-   10, i: Wall-   11, j: Gap-   12: Top half part-   13: Corner part-   14: Longitudinal rib-   20: Screw-   21: Flange-   22: Side wall-   30: Horizontal groove-   31: Bottom half part-   32: Side wall-   33: Panel shape end surface-   40: Holding part-   41: Attachment part-   42: Exterior plate-   43: Interior plate-   44: Ring-   45: Protrusion-   46: Reinforcement rib-   J: Central axis-   k: Decompression absorption panel-   L: Diagonal line

EFFECT OF THE INVENTION

The handle-equipped container of the present invention has exceptionalstorability because the transverse cross-section of the body part issubstantially quadrangular in shape. The parting line of a blow-moldingmold can be oriented in the direction of the diagonal line of thetransverse cross-sectional shape in order to attach the handle along thediagonal line, and designs on the various surfaces can be producedwithout restriction. If the handle-attaching convexity is provided tothe concavity, and the handle is attached with a gap being providedbetween the handle and the wall that surrounds the convexity forattaching the handle, then blow-molding properties will be improved bythe gap between the handle and the wall in the concavity that surroundsthe convexity for attaching the handle. As a result, the container andthe handle will undergo no incidence of separation, wrinkling, cracking,deformation, thickness irregularities caused by unsuitable stretching,or other anomalies. Additionally, uniform thickness due to suitablestretching will result; i.e., the thickness will correspond to the needfor strength. Sufficient strength will be obtained, even against dropimpact. If the container and handle are both made of polyester, anexceptional effect is obtained in regard to recyclability.

If the distance between opposite corner parts is gradually made tonarrow towards the base part in the bottom half part of the containerbelow the position where the handle is attached, the thicknessdistribution in the vicinity of the base part can be improved.

If regions of the blow-molding mold that can contact the handle aretreated so as to be heat-insulated during insert molding, it will bepossible to prevent the handle from adhering to the mold, or to preventany occurrence of deformation, whitening, heat degradation, or the like.

Making the cross-sectional shape of the holding part of the handle intothe shape of an “H” allows the weight of the handle to be reduced.Making the plate inside the holding part narrower than the exteriorplate has the effect of reducing the likelihood of the fingers, whengripping the holding part, coming into contact with the interior plate,and facilitates holding the handle.

The longitudinal compression strength of the container can be improvedby providing a longitudinal rib on a corner part of body part thatconnects to the bottom of the handle that is attached to the container.

When the handle-equipped container of the present invention isconfigured as a heat-resistant container, the handle will not come looseeven when the contents are filled at a high temperature, and a containerhaving good heat resistance can be obtained because the wall thatsurrounds the handle-attaching convexity will be heat set.

The container is blow-molded in advance so the central axis of the bodypart below the handle-attaching convexity will be inclined by 1°±0.5°toward the side of the handle-attaching convexity. The surface of theheat resistant handle-equipped container to which the handle is attacheddoes not contract, and is accordingly readily inclined. However, moldingthe container in a state wherein the axis is inclined in advance in thereverse direction has the effect of yielding overall balance, correctingthe inclination of the container, and producing a normal state. The wallsurface that surrounds the handle-attaching convexity is heat set;therefore, wrinkles tend not to form, and the handle is prevented fromcoming loose or readily detaching.

In the method for manufacturing the container of the present invention,a surface treatment is performed on at least some of the blow-moldingmold in regions for molding the handle-attaching convexity, theconcavity of the container, and the handle-attaching convexity (*2). Asa result, polyester material flows more readily in the surface treatedregions, and, conversely, less readily below the handle-attachingconvexity. Therefore, an effect is obtained whereby the polyestermaterial gathers and thickens, and increased strength is obtained belowthe handle-attaching convexity, where the load will be the greatest.

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for carrying out the present invention shall be describedbelow with reference to the drawings.

Embodiment 1

FIG. 1 is a side view of a handle-equipped container (heat-resistanthandle-equipped container) that shows an embodiment of the presentinvention. FIG. 2 is a cross-sectional view across line A-A in FIG. 1.FIG. 3 is a front view of the handle-equipped container. FIG. 4 is across-sectional view across line B-B in FIG. 3. FIG. 5 is an enlargeddrawing that shows a panel shape of an end surface of a handle-attachingconvexity. FIG. 6 is a rear view of the handle. FIG. 7 is a side view ofthe handle. FIG. 8 is a cross-sectional view across line X-X in FIG. 7.

In the drawings, a handle-equipped container 1 comprises a polyestercontainer 8 and a polyester handle 9. The polyester container 8 has afinish part 2, a shoulder part 3, a body part 4, and a base part 5 inthe stated order from the top part. A concavity 6 is provided to aportion of the body part 4. A handle-attaching convexity 7 is providedto the concavity 6. The polyester handle 9 is attached to thehandle-attaching convexity 7 of the container 8. A space 11 is providedbetween the handle 9 and a wall surface 10 that surrounds thehandle-attaching convexity 7 in the concavity 6. A transversecross-section of the body part 4 is in a substantially square shape, theconcavity 6 is in a corner part 13 of the top half part 12 of the bodypart 4, and the handle-attaching convexity 7 is positioned in theconcavity 6 along a diagonal line L of the top half part 12.

The finish part 2 of the container 8 has a thread 20 onto which a cap isscrewed, and a flange 21 therebelow. The finish part 2 extends past theshoulder part 3 to the body part 4. The body part 4 comprises a sidewall 22. The bottom part of the side wall 22 extends to the base part 5.

As stated above, the body part 4 has a transverse cross-section that issubstantially square-shaped, and is divided into the top half part 12and a bottom half part 31 by a horizontal groove 30 disposed in anintermediate position therealong. The concavity 6 to which the handle 9is attached is provided to the corner part 13 of the top half part 12.The concavity 6 is formed so that when the handle 9 is attached thereto,the handle will not protrude from the outside diameter of the body part4, and the container can be stored efficiently with the handle tightlyattached thereto. The handle-attaching convexity 7 is provided to theconcavity 6, but is positioned in the concavity 6 on a diagonal line Lof the top half part 12, and comprises a side wall 32 and a panel-shapedend surface 33. The side wall 32 is formed adequately high, and a space11 is obtained between the handle 9 and the wall surface 10 thatsurrounds the handle-attaching convexity 7.

The structure of the space 11 enables the wall surface 10 that surroundsthe handle-attaching convexity 7 to be heat set. This is achieved byhaving the mold enter between the handle 9 and the wall surface 10 thatsurrounds the handle-attaching convexity 7 when the container is to bemolded, and increasing the temperature of the mold. This is an importantconfiguration of the present invention. The panel-shaped end surface 33is formed in a flange shape, and cannot be removed when the handle 9 isattached to the handle-attaching convexity 7.

Molding the panel-shaped end surface 33 in the shape of a panelincreases the amount of processing, improves the thickness distribution,minimizes the occurrence of wrinkling during high-temperature filling,and makes it possible to greatly reduce the incidence ofcontraction-related anomalies in the container 8 and the handle 9.

A problem is presented in containers having a concavity 6 insofar as themovement of the resin worsens at the circumference thereof duringblow-molding, and the resulting effect tends to reduce the uniformity ofthe thickness distribution at the circumference of the base part, whichis where maximum stretching occurs. However, when the distance betweenopposite corner parts of the bottom half part 31 gradually becomessmaller towards the base part, the thickness distribution in thevicinity of the base part can be improved. It is preferable that thedistance between opposite corner parts gradually decreases so that thelength in the corresponding direction at the ground surface will be 55and 75% as great. It is also preferable for the distance to graduallydecrease so that the width at the ground surface in the direction alongthe diagonal lines will be substantially the same.

A longitudinal rib 14 is formed on the corner part of body part thatconnects to the bottom part of the handle (the corner part thatcorresponds to the handle attachment position on the upper end of thebottom half part 31). When a handle-equipped container such as thepresent invention is subjected to a compressive load, such as whenstacked vertically in a circulation process, stresses will beconcentrated on the body part where the bottom end of the handle is incontact, which may deform the container. However, providing thelongitudinal rib 14 to this portion can improve the compression strengthof the entire container. This is an important embodiment of the presentinvention. In Embodiment 1 pertaining thereto, a single longitudinal rib14 having a concave shape is employed; however, the longitudinal rib 14may be convex, and may comprise a combination of a plurality of ribs.

As shown in FIGS. 7 and 8, the handle 9 comprises a holding part 40 andan attachment part 41, which is attached to the handle-attachingconvexity 7 of the container 8. The cross section of the holding part 40is in the shape of an “H,” and an interior plate 43 of the holding part40 is narrower than the exterior plate 42. Therefore, the H-shapedtransverse cross-section of the holding part 40 of the handle 9 allowsthe weight to be reduced and materials to be conserved. Making thecross-sectional shape of the holding part 40 of the handle 9 into theshape of an “H” allows the weight of the handle to be reduced, andmaterials to be conserved. Making the plate 43 inside the holding partnarrower than the exterior plate 42 can reduce the likelihood of thefingers, when gripping the holding part 40, coming into contact with theinterior plate 43, and facilitates holding of the handle. The attachmentpart 41 has a ring 44 for being fitted into the handle-attachingconvexity 7 and a protrusion 45 above the ring 44. The ring 44 and theprotrusion 45 prevent the handle from detaching from the concavity 6 ofthe container 8, and being loosely connected. The reference number 46 inFIG. 4 is a reinforcement rib.

The container 8 and the handle 9 are both made from a polyestermaterial. Examples include a copolyester mainly comprising units ofpolyethylene terephthalate (PET), polybutylene terephthalate, andethylene terephthalate. The handle 9 may be made from a materialrecycled from an article molded from polyethylene terephthalate. Usingsuch a material further increases recyclability.

Next, a description shall be provided of method for manufacturing thehandle-equipped container (heat-resistant handle-equipped container) 1of the above-mentioned configuration.

First, a separate polyester handle 9 is injection-molded. A polyesterpreform that will become the container 8 is then positioned in ablow-molding mold, and the injection molded polyester separate handle 9is also positioned in the blow-molding mold. The preform is blow-moldedto form a hollow container 8. The blow-molding mold is designed in aconfiguration wherein a central axis J of the body part 4 below thehandle-attaching convexity 7 that is provided to the concavity 6 of thetop half part 12 of the body part 4 is inclined 1°±0.5° toward thehandle-attaching convexity 7. If the container is heat set in ahigh-temperature mold, it will contract somewhat on being removedtherefrom; however, the insert-molded handle will not contract.Therefore, anomalies will arise in the inclining, filling, and cappingsteps.

In the present invention, the container 1 is formed in advance in astate that is inclined in the opposite direction, whereby an overallbalance will be obtained as a result of contraction when the containeris taken out of the mold, and the inclination of the container will becorrected. The wall 32 of the handle-attaching convexity 7 is formedadequately high and sufficient room in the form of the space 11 isformed between the handle 9 and the wall surface 10 that surrounds thehandle-attaching convexity 7. As mentioned above, the mold enters thespace 11 between the handle 9 and the wall surface 10 that surrounds thehandle-attaching convexity 7; therefore, raising the temperature of themold will enable the wall surface 10 that surrounds the handle-attachingconvexity 7 to be heat set and distortion in this portion to be removedin advance.

When the container is blow-molded, and a heat-treatment is performed onat least a part of the blow-molding mold in regions for forming theconcavity 6 and the handle-attaching convexity 7 of the container 8;e.g., the top half portion of the mold that comes between the handle 9and the wall surface 10 that surrounds the handle-attaching convexity 7,then when the blow-molding is performed, the polyester material willflow more readily in the surface-treated regions of the blow-moldingmold, but flow less readily below the handle-attaching convexity 7, soas to gather and thicken. Therefore, when the heat-resistanthandle-equipped container 1 has been filled with contents and thenlifted by the handle 9, greater strength will be provided below thehandle-attaching convexity 7, where the applied load will be greatest.

According to patent document 1, a mold comes between a handle and a wallsurface surrounding a handle-attaching convexity; less area of contactis obtained between the handle and the container, which are made of thesame resin; less friction resistance occurs between the resin and thehandle during blow-molding; and the blow-molding ability is improved.However, when the temperature of the mold is increased for purposes ofperforming heat-setting, such as in the present invention, the resinwill tend to adhere to the mold, wherefore it is preferable to subjectthe surface of the mold to a surface treatment for reducing friction andadhesion with regard to the resin.

There are no specific restrictions on the method for applying thesurface treatment to the blow-molding mold, and any well-known methodcan be employed. Examples include surface roughening treatments such assandblasting and Iepco treatment, and coating treatments using Teflon®or another fluorine system.

When the container is to be blow-molded, the blow-molding mold reaches ahigh temperature in order for heat-setting to be performed. When thehandle is positioned in the blow-molding mold in order forinsert-molding to be performed, a concern arises that the handle willadhere to the mold, deform, whiten, degrade under heat, or be otherwisecompromised. The possibility is especially high for handles that aremade from polyester. However, when regions of the blow-molding mold thatare likely to contact the handle are subjected to an insulationtreatment, such concerns are eliminated, and a molded object can beproperly obtained.

The wall surface 10 that surrounds the handle-attaching convexity 7 ofthe resulting heat-resistant handle-equipped container 1 is heat-set;therefore, even if the container is filled at a high temperature such asmentioned above, wrinkles tend not to form on the wall surface 10, andit will be possible to prevent the handle coming loose and readilydetaching. When the heat-resistant handle-equipped container 1 that hasbeen filled with contents, and is then lifted by the handle 9, thegreatest load will be applied below the handle-attaching convexity 7.However, this portion is thick, and accordingly has adequate strength,for which reasons anomalies do not occur.

The superiority of the handle-equipped container of the presentinvention is shown below using a test example and a comparative example.

Test Example

The manufacturing method described above was used to fabricate atwo-liter heat-resistant handle-equipped container from a polyesterpreform that would become the container and the separateinjection-molded polyester handle.

The heat-resistant handle-equipped container was subjected to the twotests indicated below.

(1) The heat-resistant handle-equipped container was filled with twoliters of water heated to 85° C. The height from which the containercould withstand being dropped was measured once the container had cooledto room temperature.

(2) Measurements were taken of the thickness of the side wall of thebody part below the handle-attaching convexity.

Comparative Example

A two-liter-capacity heat-resistant handle-equipped container wasfabricated in the same manner as in Test Example 1, with the exceptionthat no space was provided between the handle and the wall surface thatsurrounds the handle-attaching convexity (therefore, the portion of thewall surface that surrounds the handle-attaching convexity to which thehandle is connected is not heat set), and a PFA-based release agent wasnot applied. The heat-resistant handle-equipped container was measuredin the same manner as in Test Example 1.

Five containers were used in each example as samples.

The results of the measurements are stated below.

(1) State of Handle Part

The handle of the handle-equipped container of experiment example 1remained firmly attached even after the container had been filled withhot water. By contrast, when the handle-equipped container ofComparative Example 1 was filled with water, wrinkling occurred on theperiphery of the handle-attachment part, while there were alsooccurrences of wobbliness or separation of the handle.

(2) Thickness of Side Wall of Body Part Below Handle-Attaching Convexity

The heat-resistant handle-equipped container of Test Example 1 had anaverage thickness of 0.30 mm, and no problems with the outwardappearance were encountered in regard to reduced pressure inside thecontainer. However, the handle-equipped container of Comparative Example1 had an average thickness of 0.25 mm, and the body part below thehandle deformed into the shape of a diamond, or the container buckled orexhibited other abnormalities.

(3) Results of Dropping Test

The handle-equipped container of Test Example 1 remained undamaged andexhibited no other anomalies up to a drop height of 1.2 m. However,damage could already be seen on the handle-equipped container ofComparison Example 1 at a drop height of 0.3 m.

Embodiment 1 of the present invention was described hereinabove, but thespecific configuration is not provided by way of limitation. It shall beunderstood that although the transverse cross-sectional shape of thebody part of the container is made substantially quadrangular,modifications may be suitably made within a scope that does not departfrom the main point of the present invention.

INDUSTRIAL APPLICABILITY

The handle for a container of the present invention and the container towhich the handle is attached are exceptional in regard to their storageproperties. Their industrial applicability is especially strong inapplications that require heat resistance and recyclability. Accordingto the manufacturing method, the container is blow-molded in advance sothat the central axis of the body part below the handle-attachingconvexity inclines 1±0.5° toward the handle-attaching convexity. It isaccordingly possible to obtain a handle-equipped container in which anoverall balance is obtained, the inclination of the container iscorrected, and a normal state is preserved.

Translator's Notes

-   (*1) Words in square brackets have been added by the translator for    clarity.-   (*2) The term “handle-attaching convexity” appears twice in this    sentence, which appears to be a typographical error.

1. A handle-equipped container, which comprises a polyester containerthat has a finish part, a shoulder part, a body part, and a base part inthe stated order from a top part; and that has a concavity provided to aportion of the body part; and a separate handle attached to theconcavity; the handle-equipped container being characterized in that: atransverse cross-sectional shape of the body part is substantiallyquadrangular; the concavity is in a corner part of an upper half part ofthe body part; and the handle is attached to the concavity along adiagonal line of the body part.
 2. The handle-equipped containeraccording to claim 1, wherein a handle-attaching convexity is providedto the concavity; and a space is provided between the handle and a wallsurface that surrounds the handle-attaching convexity.
 3. Thehandle-equipped container according to claim 2, wherein thehandle-equipped container is a heat-resistant handle-equipped container;and the wall surface that surrounds the convexity for attaching thehandle is heat-set.
 4. The handle-equipped container according to claim1, wherein an end surface of the handle-attaching convexity is formed inthe shape of a panel.
 5. The handle-equipped container according toclaim 1, wherein a longitudinal rib is formed on a corner part of bodypart connected to a bottom part of the handle attached to the container.6. The handle-equipped container according to claim 1, which is formedso that a distance between opposing corner parts on the bottom half ofthe body part below the handle attachment position gradually decreasestowards the base part.
 7. A handle for a container, characterized incomprising a holding part and an attachment part that is attached to ahandle-attaching convexity, wherein the holding part has a transversecross section in the shape of an “H,” and an interior plate of theholding part is narrower than an exterior plate.
 8. The handle for acontainer according to claim 7, wherein the material of the handle is amaterial recycled from articles molded from polyethylene terephthalate.9. A method for manufacturing a heat-resistant handle-equippedcontainer, comprising insert-molding a separate polyester handle onto atop part of a body part of a hollow container when the container isformed by blow-molding a polyester preform; the method for manufacturinga heat-resistant handle-equipped container being characterized incomprising the steps of blow-molding with a blow-molding mold positionedso that a central axis of the body part below a handle-attachingconvexity provided to a concavity on a top half of the body part isinclined 1°±0.5° toward the handle-attaching convexity; and heat-settinga wall surface that surrounds the handle-attaching convexity in theconcavity.
 10. The method for manufacturing a heat-resistanthandle-equipped container according to claim 9, wherein a surfacetreatment is performed on at least some of the blow-molding mold in aregion for molding the concavity of the container and thehandle-attaching convexity.
 11. The method for manufacturing aheat-resistant handle-equipped container according to claim 9, whereinan insulation treatment is performed on a region of the blow-moldingmold that can contact the handle during the insert-molding.